JP2940264B2 - Television receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a MUSE television receiver characterized by a noise reduction system.

[0002]

2. Description of the Related Art A conventional MUSE type television receiver is disclosed in, for example, JP-A-62-272879. FIG. 3 shows this conventional MUSE.
1 shows a configuration of a television receiver of a system.
Is an input terminal to which a MUSE signal is input, 2 is an input terminal 1
A / D converter for A / D converting the MUSE signal input to the A / D converter 3 is screen control information transmitted from the transmission side from the output of the A / D converter 2, for example, control information for controlling the operation of noise reduction. And a control information extraction circuit for extracting information for controlling the degree of image movement.

Reference numeral 4 denotes a frame cyclic noise reduction circuit, a frame memory 40 for storing four fields, a subtraction circuit 41, an addition circuit 42, and a non-linear processing circuit 4.
And 3. The output signal of the adding circuit 42 is supplied as one input of the mixing circuit 5 at the next stage as a signal of a still image processing system. The output signal of the A / D conversion circuit 2 is supplied to the field interpolation circuit 6 and supplied as the other input of the mixing circuit 5 as a moving image processing system signal. Reference numeral 7 denotes a motion detection circuit that detects a motion area from the output signal of the subtraction circuit 41. Reference numeral 5 denotes an output signal of the motion detection circuit 7, which is a mixing circuit that switches or mixes and outputs signals of a still image processing system and a moving image processing system. is there. A transmission line noise detection circuit 8 detects transmission line noise from a clamp line signal of a MUSE television signal.

In the conventional MUSE television receiver having the above-described configuration, control information of noise reduction transmitted from the transmission side is extracted by the noise reduction control information extracting circuit 30 and is transmitted to the nonlinear processing circuit 43. Supply. The quality of the transmission line is determined by the transmission line noise detection circuit 8.
And when it is below a predetermined level, the detection result is supplied to the non-linear processing circuit 43. The nonlinear processing circuit 43 is RO
M, the response characteristic is controlled by the control information of the noise reduction and the detection result of the transmission line noise, the noise reduction processing is performed, and the S / N is improved. Therefore, when the quality of the transmission path is poor or when the S / N of the image of the transmission source is equal to or less than a predetermined value, the noise reduction processing is performed on the receiving side.

[0005] Next, motion control information (for example, when the entire screen is a complete still image, when it is a quasi-still image that has little movement but can be regarded as a still image, at the time of a scene change, or when the movement is more intense than usual) The motion control information extraction circuit 31 extracts the control information and supplies the control information to the motion detection circuit 7. The motion detection circuit 7 detects the motion of each pixel based on the correlation result between frames or between two frames, and supplies the detection signal to the mixing circuit 5. When the motion control information is supplied, the control information is given priority. Is output. That is, when complete still image information is transmitted, all motion signals detected by the motion detection circuit 7 on the receiver side are turned off, and a still image signal is forcibly selected.
The mixing circuit 5 performs switching or mixing processing between a still image area and a moving image area based on an output signal of the motion detection circuit 7 and outputs the result.

[0006]

However, in the conventional configuration as described above, the noise reducer is based only on the control information for controlling the operation of the noise reducer transmitted from the transmitting side and the result of the transmission line noise detected on the receiving side. Is controlled. Therefore, there is no problem in the case of an image originally having a good S / N and little noise on the transmission line, such as an image taken in a studio, but for example, an image with insufficient camera performance or a VTR having repeated dubbing several times. In the case of the reproduced image of the above, if the image is near the limit where the noise reducer is not required and the quality of the transmission path on the receiving side is reduced to the limit of the predetermined value, the operation of the noise reducer is not performed.

In view of the above, the present invention uses motion control information in addition to noise reduction control information transmitted from the transmission side or detection results of transmission noise on the reception side, particularly when the entire screen is close to a still image. The object of the present invention is to provide a MUSE television receiver which controls the operation of a noise reducer to the highest level and has a good S / N ratio.

[0008]

SUMMARY OF THE INVENTION The present invention provides control information for controlling the operation of noise reduction and control of the movement of an image.
Television receiving a television signal with control information superimposed
A vision receiver, a control information extraction circuit for extracting control information of the noise reduce and control information of the motion,
A transmission line noise detection circuit for detecting the noise of the transmission path, before
Output signal of control information extraction circuit and transmission line noise detection circuit
And a noise reduction circuit, and a noise reduction circuit is provided by an output signal of the OR circuit.
It is characterized by changing the characteristics of the road .

[0009]

According to the present invention, the motion control information transmitted from the transmitting side is extracted by the motion control information extracting circuit by the above-described configuration.
If it is complete still image control information, the operation of the noise reduction is controlled to the highest level, and the S / N is improved.

[0010]

FIG. 1 shows the configuration of a television receiver according to an embodiment of the present invention. In FIG. 1, components performing the same operations as those in the related art are denoted by the same reference numerals and description thereof is omitted. Reference numeral 10 denotes an OR circuit. The OR circuit 10 includes a noise reduction control information extraction circuit 30 and a motion control information extraction circuit 3.
1 and the output signal of the transmission noise path detection circuit 8 are supplied,
Perform logical sum processing. The output signal of the OR circuit 10 is supplied to the nonlinear processing circuit 43 of the noise reduction circuit 4 to control the operation of the noise reduction.

The operation of the thus-configured television receiver of this embodiment will be described below with reference to the waveform diagram of FIG. In FIG. 2, reference numeral 310 denotes a noise reduction control information extraction signal, 320 denotes a motion control information extraction signal.
If there is no data, it is indicated by the level of “0”. Reference numeral 80 denotes a transmission line noise detection signal, which is output when it is higher than a predetermined noise level.
It is indicated by the level of “1”, and when it is small, it is indicated by the level of “0.” Although this waveform diagram shows all states, normally, the noise reduction control information and the transmission line noise detection signal are almost fixed to “0”. It has been done.

The MUSE signal input from the input terminal 1 is A / D converted by the A / D conversion circuit 2 and supplied to the control information extraction circuit 3 and the transmission line noise detection circuit 8. Noise reduction control information extraction circuit 30 of control information extraction circuit 3
Detects noise reduction control information,
To its output signal 310. Also, when the motion control information extraction circuit 31 detects the control information signal of the complete still image of the motion control information, the output signal 3
Supply 20. Further, when the transmission line noise detection circuit 8 detects noise of a predetermined level or more, the output signal 8
0 is supplied to the OR circuit 10. Each output signal 310, 320, 80 supplied to the logical sum circuit 10 is subjected to logical sum processing and supplied to the non-linear processing circuit, and the operation of noise reduction is performed in the period of FIG. 2A, thereby improving the S / N. Is achieved.

As described above, according to this embodiment, the noise reduction operation can be performed even with the extraction result of the motion control information, and the S / N of the image can be further improved. In particular, since noise reduction operates on a completely still image, there is no adverse effect such as multi-line blurring that occurs in an image having a sharp movement as in the related art.

In the present embodiment, the motion control information detection circuit performs the noise reduction operation when the complete still picture information is detected. Is also good. Further, the noise reduction operation may be controlled in multiple stages according to the type of motion information.

[0015]

As described above, according to the present invention,
The noise reduction operation can be performed even with the result of the transmitted motion control information, the S / N improvement of the image can be further improved, and the practical effect is great.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a television receiver according to an embodiment of the present invention.

FIG. 2 is an operation waveform diagram of the embodiment.

FIG. 3 is a block diagram showing a configuration of a conventional television receiver.

[Explanation of symbols]

 Reference Signs List 3 control information extraction circuit 4 noise reduction circuit 8 transmission line noise detection circuit 10 OR circuit 30 noise reduction control information extraction circuit 31 motion control information extraction circuit 43 non-linear processing circuit

Claims (1)

(57) [Claims] 1. A television receiver for receiving a television signal on which control information for controlling operation of noise reduction and control information for controlling movement of an image are superimposed.
A control information extraction circuit for extracting the control information of the control information and the motion of the serial noise reduce, the transmission line noise detection circuit for detecting the noise of the transmission path, the transmission path and the control information extraction circuit
An OR circuit for performing an OR operation on an output signal of the noise detection circuit;
A noise reduction circuit; and an output of the OR circuit.
A television receiver wherein the characteristics of a noise reduction circuit are changed by a signal .